It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said three times: "There is no sin (in anything) except in killing a Muslim."
Imam al-Tabarani (may Allah have mercy on him) said: "No one narrated this hadith from Muhammad Ibn al-Hanafiyyah except Mundhir, no one from Mundhir except Layth, no one from Layth except Abu Ja'far, and no one from Abu Ja'far except Hakkam, and Ishaq bin Rahawayh is alone in narrating it."
Hadith Referenceالمعجم الأوسط / باب الميم / 8148
Hadith Gradingمحدثین:إسناده ضعيف، فيه ليث بن أبي سليم وهو مدلس
Hadith Takhrij«قال الهيثمي: فيه ليث بن أبي سليم وهو مدلس «مجمع الزوائد ومنبع الفوائد، ج 7، ص 297»»